Is it possible to use differents radius preset filters importing with avisynth ?

I have a video has two very different noise sequences, with the second stronger than the first. The first preset has a temporal radius of 3, the second preset has a temporal radius of 4.

If you're wondering what kind of video can have this, Ray Harryhausen's movies. Special effect scenes have a stronger noise than normal scenes. Difference is so noticeable that you see that you'll have a special in the scene you're watching even before the special effect orcurs...

The last time we checked preroll in Avisynth it didn't work correctly and had no influence on the results. I recommend to try different values of that parameter to see whether it produces any difference at all. If it works, then perhaps something like that could be used:

1. select the maximum required preroll (4 in this case);
2. when you apply the filter to a segment requiring a temporal filter radius of 3, use a bit larger segment, like trim(video,199,299)

Another approach would be to use the weaker filtration over the whole video first (or excluding the special segments) and then additionally clean the segments requiring special treatment.

Alternatively, the Mix with Original option could probably help if you used the largest radius everywhere but compensated its stronger filtration in less noisy segments by using presets with the Mix with Original option enabled.